Development Of Vegetation Communities Research Articles

Vegetation community dynamics during naturalized developmental restoration ofPinus tabulaeformisplantation in North warm temperate zone

AbstractThe study is to explore the dynamics of community structure, diversity, interspecific relationships and stability during naturalized developmental vegetation restoration which realized by natural interaction between plantation and native trees without human’s involvement. The naturalized developmental restored forests in Baxianshan National Reserve were divided into three typical stages (i.e. Pinus tabulaeformis forest stage, mixed forest stage and near-natural forest stage) according to the ratio of P. tabulaeformis coverage to arbor layer, and the zonal natural secondary forests for control. According to the data of each wood gauge, we focused on the dynamics of community in terms of structure, diversity and stability. We found that, (i) The composition of dominant populations kept stable since the mixed forests stage and the α-diversity increased with restoration; (ii) The diameter class structure of tree layer exhibited a tendency of bell-shaped type toward inverted J-type, indicating an active regenerating and developmental status; (iii) Niche width of dominant populations such as Juglans mandshurica, Quercus mongolica, Quercus variabilis and Tilia amurensis increased during restoration, while that of Quercus dentata population decreased after playing a pioneer role; (iv) The proportion of negative association and high niche overlapped population pairs (>0.5) both decreased with restoration. In summary, naturalized developmental restoration has promoted the actively developing and regenerating of populations and improved the healthy restoration of plantation community. The status and interrelationships of populations were still being adjusted. The results provide a reference for revealing the dynamic characteristics of vegetation community development in naturalized developmental restoration of plantations.

Monitoring spatial and temporal dynamics of wetland vegetation and their response to hydrological conditions in a large seasonal lake with time series Landsat data

Periodic hydrological processes of seasonal lakes are the dominant factors leading to the development of vegetation communities and ecological processes. Dongting Lake is a typical seasonal lake in the middle and lower reaches of the Yangtze River and its hydrological conditions have changed significantly due to the construction of the Three Gorges Dam (TGD). However, there are knowledge gaps in the responses of wetland vegetation dynamics to the changes of hydrological conditions, especially in cloudy and rainy regions, where continuous large-scale monitoring is still challenging. In this study, by using time series of Landsat data on Google Earth Engine, a long-term cloudless remote sensing images dataset of Dongting Lake during the dry season was constructed. The multi-year wetland vegetation from 2003 to 2020 was mapped using the random forest model. Relationships between wetland vegetation dynamics and hydrological conditions (e.g., water level and inundation character) were examined using correlation and linear analysis. Results revealed that wetland vegetation in the Dongting Lake experienced significant inter-annual spatial heterogeneity and temporal dynamic equilibrium with a slight increase during the post-TGD period. Only Carex communities at elevations above 28 m and below 26 m displayed apparent changes. Reed communities have relatively high selectivity to inundation frequency, and are affected mainly by changes in water levels during the dry season of the current year. Hydrological conditions during the rising period have an important impact on the first growth and reproduction stage of Carex, while higher water levels or more rapid surface submergence lead to a decrease in seed density in the soil of low-elevation floodplains. This study deepens our knowledge of changes of wetland vegetation and their response to hydrological conditions, and is of great significance to the ecological protection and restoration of Dongting Lake.

UAV-based classification of maritime Antarctic vegetation types using GEOBIA and random forest

Development of vegetation communities in areas of Antarctica without permanent ice cover emphasizes the need for effective remote sensing techniques for proper monitoring of local environmental changes. Detection and mapping of vegetation by image classification remains limited in the Antarctic environment due to the complexity of its surface cover, and the spatial heterogeneity and spectral homogeneity of cryptogamic vegetation. As ultra-high resolution aerial images allow a comprehensive analysis of vegetation, this study aims to identify different types of vegetation cover (i.e., algae, mosses, and lichens) in an ice-free area of Hope Bay, on the northern tip of the Antarctic Peninsula. Using the geographic object-based image analysis (GEOBIA) approach, remote sensing data sets are tested in the random forest classifier in order to distinguish vegetation classes within vegetated areas. Because species of algae, mosses, and lichens may have similar spectral characteristics, subclasses are established. The results show that when only the mean values of green, red, and NIR bands are considered, the subclasses have low separability. Variations in accuracy and visual changes are identified according to the set of features used in the classification. Accuracy improves when multilayer information is used. A combination of spectral and morphometric products and by-products provides the best result for the detection and delineation of different types of vegetation, with an overall accuracy of 0.966 and a Kappa coefficient of 0.946. The method allowed for the identification of units primarily composed of algae, mosses, and lichens as well as differences in communities. This study demonstrates that ultra-high spatial resolution data can provide the necessary properties for the classification of vegetation in Maritime Antarctica, even in images obtained by sensors with low spectral resolution.

Ecological gradients hosting plant communities in Himalayan subalpine pastures: Application of multivariate approaches to identify indicator species

The development of vegetation communities is typically influenced by their response to variation in environmental, geographic and as well as physiographic gradients. The current study was planned to evaluate the influence of environmental gradients upon the structure of plant communities and to highlight their respective indicators in subalpine pastures of the Himalaya, Pakistan. In relation to this aim, ecological techniques were used following the Line transect (50 m) method to quantify the vegetation structure of the study area. Soil samples were collected from each sampling site and edaphic gradients were examined using standard protocols. Weather station data (Kestrel 4000) was used to determine the climatic gradients, GPS data was used to record the geographic and physiographic gradients. PCORD software was used to recognize communities through two-way indicator species analysis (TWINSPAN), R and CANOCO software was employed for ordination analysis to find variation directories of different plant species. A total of 56 plant species, recorded from 21 sampling sites, were grouped into four plant communities with the help of environmental gradients. The highest index of similarity was recorded between the Bergenia-Sibbaldia-Rheum and Sibbaldia-Rheum-Bergenia communities and highest dissimilarity between Bergenia-Sibbaldia-Rheum and Juniperus-Sibbaldia-Poa communities. The highest number of plant species (50 species), maximum alpha diversity (H′ = 3.38) and beta diversity was reported in Sibbaldia-Rheum-Bergenia community (0.95), but Pielou's evenness was highest (0.89) in Juniperus-Sibbaldia-Poa among all recorded communities. Besides, the edaphic (i.e. organic matter, phosphorous, pH and soil texture) and climatic factors (temperature, humidity) were the strong environmental gradients that were responsible for structuring and hosting the diverse plant communities in subalpine meadows. Techniques adapted in the current study for identification of vegetation indicators could further be used for conservation management.

Lithoecotopes and Vegetation on Dumps of the Central Mining and Ore Enrichment Combine (the central zone of Kryvbass)

In the article, characteristics of development of vegetation communities under conditions of mine rock dumps of the Central Mining and Ore Enrichment Combine or their rocky components (lithoecotopes) were determined, namely only lithophilic vegetation. We сlassified various lithoecotopes and characterized vegetation communities of varying complexity growing on plateau tops, terraces and slopes, depending on specifics of their constituent rocks and typological features. In accordance with the state of lithoecotopes, including all typological characteristics and the geochemical nature of the rocks, plant lithophilic communities growing on the dumps of the Central Mining and Ore Enrichment Combine, were characterized by significant differences in analytical (floristic and ecomorphic composition, occurrence, layerage, aspect, abundance, cover) and synthetic (similarity, constancy) signs. A detailed survey of the state of plants and their communities within the lithoecotopes has allowed us to establish that their distribution and development have clearly expressed dependence on substrate and relief-exposure,which can be used in phytocoenic and phytocenotic melioration of such technogenic ecotopes. Native overgrowth of all dumps has a shrub-tree forest and grassy pattern in accordance with the typological characteristics and rock composition. In general, taxonomic composition of plant communities growing on the dumps of the Kryvbas central zone is characterised by 153 species belonging to 31 families, of which 66 species are petrophytes, and 18 species are typical only for zone surveyed.

Mid- and Late Holocene vegetation dynamics and fire history in the boreal forest of European Russia: A case study from Meshchera Lowlands

Climate, fire, and human activities strongly affected the development of vegetation communities during the Holocene, yet the relative importance of these individual factors remains unclear in many areas. This paper presents new multi-proxy records of environmental change for the Meshchera Lowlands (the central part of the East European Plain) during the Holocene. Changes in regional vegetation during the Mid- and Late Holocene were influenced by climate, fire regime and human impact, as indicated by pollen, plant macrofossil, charcoal and testate amoebae analysis from several peat cores, along with reconstruction of tree cover from pollen assemblages. Since 8500calyrBP, the vegetation history represented a series of consecutive phases of birch, birch-pine and pine-broadleaf forests, with introduction of spruce after 2500calyrBP. Maximal abundance of broadleaf tree species was detected from 4700 to 2000calyrBP. Vegetation dynamics were strongly influenced by human activity since 1400calyrBP. High fire frequency was recorded for the periods 8500–4500calyrBP and 3500–2000calyrBP, when the fire return interval varied from 40 to 80years. Since 2000calyrBP, the fire return period exceeded 500years suggesting a significant decline in fire frequency during the last two millennia.

Ecological Analysis Before and After Planting in a Constructed Wetland in the Adirondacks

The assessment of constructed treatment wetland success usually relies on abiotic measures, such as nutrient level reduction. Because constructed wetlands eventually function as whole ecosystems, and their biotic components play a role in water treatment, it is important to consider the development of associated flora and fauna when conducting site assessments. The goal of this two-year case study was to observe ecosystem establishment at a constructed stormwater treatment wetland adjacent to Lake George in the Adirondack Mountains of New York, with a focus on macroinvertebrate and vegetation community development. The first year of the study occurred during a period of natural succession. The second year occurred following the artificial introduction of 85 plant species. The vegetation community predictably improved in richness, evenness, and diversity. The macroinvertebrate community experienced substantial shifts in dominant taxa. Importantly, each pond in the wetland’s treatment train developed unique profiles over time as defined by their vegetation and macroinvertebrate communities, as well as by their water chemistry. While the specific biotic and abiotic drivers creating these unique ponds have not been identified, the disparate profiles and how they function together will determine stormwater treatment efficiency after further site maturation.

Plant community development as affected by initial planting richness in created mesocosm wetlands

The gain or loss of plant species may alter the development of structural and functional attributes critical to developing or restoring ecosystem services in created mitigation wetlands. A three-year study was conducted in created mesocosm wetlands to determine the role of initial planting richness (IPR) in vegetation community development using five species of plants common to natural and created wetlands in the Virginia Piedmont. The mesocosms were naturally colonized by volunteer species after planting the same as in real-world mitigation wetlands created in the region. At the end of each growing season, all species present were identified, and species richness (S) and cover percentages (i.e., percent total, planted and volunteer species) were measured. Indices for diversity (Shannon–Weiner H′) and prevalence (PI) were calculated. After establishment of planted rhizomes, hydrology was maintained solely by precipitation. However, unintended leaking in six mesocosms in the beginning of the study created two distinctively different hydrologic conditions (i.e., wet vs. dry conditions) that were factored into the final data analysis. Both richness (S) and biodiversity (H′) varied significantly with initial planting richness (IPR). Differences in these two attributes were mainly due to differences between monotypic mesocosms (IPR=1) and those with the greatest number of species initially planted (IPR=5). Hydrologic conditions impacted some of the plant community characteristics, including total percent cover being higher in one year and PI being lower both in “wet” conditions. The mesocosms were becoming typical of wetlands with more hydrophytes present over the course of the study. The outcome of the study showed that the mesocosm wetlands were following a similar pattern found in vegetation community development trajectory of newly created mitigation wetlands. The study showed the positive effect of initial planting richness on species richness and diversity in the early development of plant community. Our findings also reinforce the importance of maintaining adequate hydrologic conditions for the early development of vegetation community in created mitigation wetlands.

Predictive occurrence models for coastal wetland plant communities: Delineating hydrologic response surfaces with multinomial logistic regression

Understanding plant community zonation along estuarine stress gradients is critical for effective conservation and restoration of coastal wetland ecosystems. We related the presence of plant community types to estuarine hydrology at 173 sites across coastal Louisiana. Percent relative cover by species was assessed at each site near the end of the growing season in 2008, and hourly water level and salinity were recorded at each site Oct 2007–Sep 2008. Nine plant community types were delineated with k-means clustering, and indicator species were identified for each of the community types with indicator species analysis. An inverse relation between salinity and species diversity was observed. Canonical correspondence analysis (CCA) effectively segregated the sites across ordination space by community type, and indicated that salinity and tidal amplitude were both important drivers of vegetation composition. Multinomial logistic regression (MLR) and Akaike's Information Criterion (AIC) were used to predict the probability of occurrence of the nine vegetation communities as a function of salinity and tidal amplitude, and probability surfaces obtained from the MLR model corroborated the CCA results. The weighted kappa statistic, calculated from the confusion matrix of predicted versus actual community types, was 0.7 and indicated good agreement between observed community types and model predictions. Our results suggest that models based on a few key hydrologic variables can be valuable tools for predicting vegetation community development when restoring and managing coastal wetlands.

Experimental wet heath translocation in Dorset, England

Heathland has become fragmented throughout its European range with many countries losing 60–90% of their heathland area during the 20th century. A small, isolated area of wet heathland within permitted ball clay workings in Dorset (England) was translocated in October 1993 to an engineered receptor cell fed by groundwater and direct precipitation in order to mitigate the otherwise total loss of the wet heath. The aims were to rescue the wet heathland and to re-establish a community type similar to the wet heath that originally occurred at the donor site prior to the recent development of vegetation communities and birch colonisation associated with drier conditions. Vegetation monitoring over 12 years up to 2005 indicated that the experimental translocation successfully fulfilled the aims for a period of 7 years when the hydrological regime of the receptor site was actively managed. There was development of a mosaic of wet heath and mire vegetation community types including Sphagnum lawns and open bog pools. However, when active management ceased, the receptor site became drier and species were lost. Multivariate analysis revealed a trajectory of progressive rapid chronological change during 1994 and 1995 followed by a period of relative stability between 1996 and 2000 which coincided with greater species density. Subsequently up to 2005, the plant community became less species-rich and the plant community reverted to a species structure similar to that which occurred in 1994/1995. The importance of hydrological regime for plant community structure was tested using fixed-quadrat data and the water level measurements made in the period 1995–1998. Canonical Correspondence Analysis (CCA) multivariate analysis revealed a hydrological gradient with a significant seasonal effect of water table depth in the first half of the year and close association of the least wet quadrat location and non-mire species. Overall, the results support the use of translocation as a means of rescuing wet heath habitat which would otherwise be lost due to change in land use. There is a risk of failure when translocating a complex ecosystem such as wet heath but ecological engineering provides an insight into defining the risk. Our results demonstrated that an ecologically acceptable outcome for a wet heath translocation can be achieved with careful design and implementation and sensitive management of the receptor site. However, it is essential to secure long-term hydrological and vegetation management in order to provide a sustainable outcome for long-term survival of a target wet heath community.

Plant community development in the first growing season of a created mitigation wetland bank as influenced by design elements

Vegetative communities of created wetlands often display lower species richness, less cover, higher occurrence of non-native or invasive species, and fewer obligate wetlands species than those in natural wetlands, thus failing to meet basic success criteria for wetland mitigation. This study examined the effects of two design elements, disking-induced microtopography and hydrologic regime, on the first year vegetation development pattern of a mitigation wetland newly created in the Virginia piedmont. Elevation and species cover were measured along replicate multiscale circular transects in two adjacent wetland sites that are different in their hydrologic regime. Two microtopographic indices, tortuosity (T) and limiting elevation difference (LD), were calculated from the elevation measurements. Both indices were higher in disked plots than non-disked plots, showing the effect of disking on microtopography. Out of forty-one vegetation taxa observed in the wetland, 29 taxa were naturally colonized and 12 taxa were seeded. All plots except one non-disked plot were dominated by wetland vegetation. Species richness and diversity were higher in disked than in non-disked plots. Vegetation community development seemed also influenced significantly by hydrologic regime of the site. The effect of microtopography on species richness and diversity was more pronounced in a relatively dry site compared to a wet site. In addition, percent cover, species richness and diversity of vegetation were positively correlated with microtopographic indices such as T and LD. Two design elements, microtopography and hydrologic regime, should be considered and incorporated in wetland creation to enhance plant community development.

Vegetation succession among and within structural layers following wildfire in managed forests

Question: How does vegetation develop during the initial period following severe wildfire in managed forests? Location: Southwestern Oregon, USA. Methods: In severely burned plantations, dynamics of (1) shrub, herbaceous, and cryptogam richness; (2) cover; (3) topographic, overstory, and site influences were characterized on two contrasting aspects 2 to 4 years following fire. Analysis of variance was used to examine change in structural layer richness and cover over time. Non-metric multidimensional scaling, multi-response permutation procedure, and indicator species analysis were used to evaluate changes in community composition over time. Results: Vegetation established rapidly following wildfire in burned plantations, following an initial floristics model of succession among structural layers. Succession within structural layers followed a combination of initial and relay floristic models. Succession occurred simultaneously within and among structural layers following wildfire, but at different rates and with different drivers. Stochastic (fire severity and site history) and deterministic (species life history traits, topography, and pre-disturbance plant community) factors determined starting points of succession. Multiple successional trajectories were evident in early succession. Conclusions: Mixed conifer forests are resilient to interacting effects of natural and human-caused disturbances. Predicting the development of vegetation communities following disturbances requires an understanding of the various successional components, such as succession among and within structural layers, and the fire regime. Succession among and within structural layers can follow different successional models and trajectories, occurs at different rates, and is affected by multiple interacting factors.

Characterization of microtopography and its influence on vegetation patterns in created wetlands

Created wetlands are increasingly used to mitigate wetland loss. Thus, identifying wetland creation methods that enhance ecosystem development might increase the likelihood of mitigation success. Noting that the microtopographic variation found in natural wetland settings may not commonly be found in created wetlands, this study explores relationships between induced microtopography, hydrology, and plant species richness/diversity in non-tidal freshwater wetlands, comparing results from two created wetland complexes with those from a mature reference wetland complex in northern Virginia. Elevation, steel rod oxidation depth, and species cover were measured along replicate multiscale (0.5 m-, 1 m-, 2 m-, and 4 m-diameter) tangentially conjoined circular transects in each wetland. Microtopography was surveyed using a total station and results used to derive three roughness indices: tortuosity, limiting slope, and limiting elevation difference. Steel rod oxidation depth was used to estimate water table depth, with data collected four times during the growing season for each study site. Plant species cover was estimated visually in 0.2 m2 plots surveyed at peak growth and used to assess species richness, diversity, and wetland prevalence index. Differences in each attribute were examined among disked and non-disked created wetlands and compared to a natural wetland as a reference. Disked and non-disked created wetlands differed in microtopography, both in terms of limiting elevation difference and tortuosity. However, both were within the range of microtopography encompassed by natural wetlands. Disked wetlands supported higher plant diversity and species richness than either natural or non-disked wetlands, as well as greater within-site species assemblage variability than non-disked wetlands. Irrespective of creation method, plant diversity in created wetlands was correlated with tortuosity and limiting elevation difference, similar to correlations observed for natural wetlands. Vegetation was more hydrophytic at disked sites than at non-disked sites, and of equivalent wetland indicator status to natural sites, even though all sites appeared comparable in terms of hydrology. Results suggest that disking may enhance vegetation community development, thus better supporting the goals of wetland mitigation.

Development of Vegetation Communities in a Retrogressive Thaw Slump near Mayo, Yukon Territory : A 10-year Assessment

The vegetation in a retrogressive thaw slump, first surveyed and documented in 1987, was revisited 10 years later to investigate its subsequent development and to test a chronosequence-based successional model. The thaw slump stabilized in 1994, when the headwall became covered by organic and mineral debris. As a result, the meltwater supply from headwall ablation ceased. Alteration of environmental conditions due to stabilization of the headwall diverted the vegetation succession from the chronosequence determined in 1987. Areas that were marshy in 1987 dried up, and an area dominated by Polygonum alaskanum appeared close to the headwall. Much of the thaw slump was dominated by Salix spp. in 1997, rather than the Equisteum of 1987. However, the ground more than 200 m from the headwall, over a decade old in 1987, experienced less change in edaphic conditions, and the communities there continued to develop a structure approaching the surrounding undisturbed forest.

Spider communities as tools in monitoring reclaimed limestone quarry landforms

Spider communities are sensitive to a wide range of environmental factors and are potential ecological indicators which may be effective in the assessment and monitoring of restored ecosystems. One restoration technique of disused limestone quarry faces, landform replication, attempts to create landforms and ecosystems similar to those found on natural dalesides. Vegetation surveys indicate that communities developing on landform replications are more closely allied to natural dalesides than are those of naturally recolonised disused quarries. Assessment of the spider communities of three landform replication sites, a natural limestone daleside and seven naturally recolonised disused limestone quarries, using DECORANA and TWINSPAN, produced differing patterns of sites than those observed through the assessment of the vegetation communities. DECORANA assessment based on vascular plant species composition highlights the similarities between daleside and reclaimed site communities. The sensitivity of spider communities to vegetation structure and extent of bare ground highlights differences between sites and provides evidence of important differences in vegetation community development particularly in relation to cover and structure. Implications for the assessment of reclamation and restoration techniques are discussed.

Impact of tephra fall and environmental change: a 1000 year record from Matakana Island, Bay of Plenty, North Island, New Zealand

Abstract Palynological evidence was used to determine the development of vegetation communities on Matakana Island, North Island, New Zealand, over the last 1000 radiocarbon years. The pollen record indicates that changes occurred in the vegetation immediately following fallout deposition of the Kaharoa Tephra approximately 100 km from source at c. 665 years BP. Such changes may be a direct response to the impact of tephra fall, although the possibility of anthropogenic disturbance cannot be discounted. As a result of the eruption some taxa ( Leucopogon fasciculatus and Tupeia antarctica ) became at least temporarily extinct from the area. Two phases of anthropogenic influence on the environment are recorded in the pollen record: Polynesian, followed by European inhabitation of the island, giving a detailed history of human influence in the area for the millennium.

The nature and evolution of lithotypes in the tertiary brown coals of the Latrobe Valley, southeastern Australia

Lithotype banding, identified on colour and texture of the coal, occurs in all seams covering the period Mid Eocene to Late Miocene in the Latrobe Valley. Preliminary palaeobotanical studies on both pollen and plant macrofossil components of the youngest seams indicated strong relationships between lithotype, vegetation and inferred depositional environment with the lithotype gradient from lightest to darkest coals corresponding with hydroseral stages from unvegetated open water-through swamp forest-to raised bog communities. Subsequent studies on the older seams failed to show such close correspondence between lithotype and vegetation. The analysis of palynological and petrological data from all seams in this paper adds support to the original hypothesis of lithotype formation. However, it also demonstrates a gradual differentiation of lithotypes through the coal-forming period. This most likely involved the progressive development of vegetation communities adapted to the range of swamp environments with the peatforming environment. Of particular significance is the development of a community with a significant sclerophyll component within the predominant rainforest vegetation, which colonised the raised bogs of the youngest seams. The process may have been facilitated or accelerated by an increasingly variable climate and the increased importance of fire within the region.